Whatever you have planned this evening, I suggest you clear some time in your busy schedule to play a little Tupsu. What is Tupsu? It's a physics-based puzzler that you can play on your Android device, and you can leave the (Google) wallet in your (virtual) pocket – Tupsu is totally free.

Tupsu (the thing, not the game) is a furry little ball with sticky eyes on long flexible stalks. This title has a World of Goo style of gameplay. You have to drag the sticky eyes over to platforms, where the elastic action will pull the creature along. Tupsu starts out with just the one eye, but it starts growing more like an out of control mutant the longer you play. You'll use this movement mechanic to swing, drag, and slingshot to the end of 30 challenging levels.

The physics, graphics, and music in Tupsu are impressive – so impressive that I find myself surprised that the developer isn't asking for any money. The iOS version of this game appears to be identical and does cost $0.99, so call this one a win for Android. I would probably pay for additional levels of Tupsu, but there is no option to do so at this time.